Docker's volume list has no size, so add a "Compute sizes" button that runs
`docker system df` (via client.df()) and shows per-volume size in a new Size
column. The df walk is expensive (seconds), so results are cached ~60s and
loaded on demand instead of on every poll.
- volume_service.volume_sizes(force) with a 60s TTL cache; GET /api/volumes/sizes
+ agent /agent/volumes/sizes + proxy /api/agents/{id}/volumes/sizes.
- Frontend: volumesApi.sizes(force, agentId); Volumes page gained a Size column
and a Compute sizes button (per host) that triggers the lookup.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Adds a dedicated Volumes page (sidebar) with per-host sections (local + each
online agent), matching the Networks/Images layout. Lists volumes with driver,
owning stack, in-use containers and mountpoint; admins can delete (with an
in-use warning + force option) and prune unused, plus an "only unused" filter.
- agent_app.py: /agent/volumes (list/delete with in-use 409 guard/prune)
reusing volume_service.
- routers/agents.py: proxy routes /api/agents/{id}/volumes/* (audit-logged
delete/prune).
- Frontend: volumesApi list/remove/prune take an optional agentId; new
pages/Volumes.tsx (VolumesSection per host) + sidebar entry + /volumes route.
The volume wizard (generate-yaml/host paths) stays local and unchanged.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
